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Becoming a CCIE is a lot about technology, but it is also a mental game. Many people forget this aspect. What do I mean with this?

Yes, we need to know the technology inside out but we also need to get to a level of thinking where we can easily identify potential issues. Look at a diagram with OSPF and see, oh that is not going to work, it is not connected to area 0. We will need a virtual link later.

If doing mutual redistribution from RIP to OSPF then there is a potential for suboptimal routing and routing loops (higher AD -> lower AD -> higher AD). BTW, don’t care about suboptimal traffic unless told to, we don’t have time for this.

If doing multicast draw out the topology, where will the source and shared tree be rooted? What interfaces are the RPF interfaces?

If I’m told to make sure BB routers does not receive routing updates, what are my options of filtering this?

So am I at a CCIE level of thinking? I’m not sure but I do know that I am a lot closer to it then when I started my journey. The learning experience has been immense. In 3 months from now we will know if I was at the right level 🙂

Difficult finding time for posts lately. I am deep into studies. I have now passed 500h preparing for the lab. My focus right now is mainly Vol1 labs with a Vol2 lab every other week. Towards the end my focus will shift to doing Vol2 labs, mock labs and Vol4 labs. My progress is good but I still feel short of time.

Tonight it is time for some BGP labs. It is one of my favourite protocols. If I find the time I might do a post about BGP, maybe on Conditional Route Injection or something fun like that 🙂

Finished OSPF Vol1 tonight. I should know pretty much everything about OSPF by now. Here are some advice that I think is good when handling OSPF.

show ip ospf data self-originate – Will show what LSAs the local router is generating

show ip ospf data summary 150.3.0.0 adv-router 150.8.4.4 – Will show the Type3 inter-area summary as advertised by the router 150.8.4.4 (Router-ID)

show ip ospf border-routers – Shows the cost of reaching ABR and ASBR, a nice shortcut for finding the forward metric when you are looking at external routes. You can find this out yourself by checking costs of the links to reach the advertising router but this is a nice shortcut.

show ip ospf data | be Type-7 – Will start the OSPF database output for the NSSA external prefixes, change Type to whatever you want to look at.

These are some of my favourites, what commands do you use yourselves? Post in comments.